6. Put an acute accent over the second vowel of a hiatus if the vowel is i or u, except when they are followed by a syllable-final z or by nh, or if the vowel sequence is ii.

hiatus = sequence of two vowels uttered in different syllables.

Saara (Sahara)

empreendedor (entrepreneur)

xiita (shiite)

saída (exit)

graúdo (great, important)

cuíca (Brazilian drumlike insturment that produces a grunting sound)

raízes (roots)

but not

raiz (root)

bainha (hem)

7. Put a dieresis over u in the groups gu and qu when the u is clearly pronounced and followed by e and i.

ungüento (ointment)

qüingentésimo (five hundredth)

qüinquagésimo (fiftieth)

but not

Guanabara (a place in Brazil)

guerra (war)

quinto (fifth)

queijo (cheese)

8. Prepositions and object pronouns do not take any accents.

Exceptions: através de (through), atrás de (behind).

por (for)

de (of)

em (in, on, at)

se (if)

nos (us)

vos (you, thee)

9. The grave accent is only used to indicate crase (crasis), that is, the contraction between preposition a and feminine articles a(s)or demonstrative pronouns aquele(s), aquela(s) and aquilo.

Crase occurs whenever preposition a is followed by the words above.

For other uses of the grave accent, read Crasis & combinations.

às = a + as

àquele = a + aquele

àquela = a + aquela

àquilo = a + aquilo

10. Sometimes homógrafos (homographs - words with the same spelling) have an accent (called acento diferencial) to make the difference between the words clear.

pode (3rd person singular, present indicative, verb poder - can)

pôde (3rd person singular, perfect indicative, verb poder - can)

por (for)

pôr (put, to lay, to set)